1. Field of the Invention
The present invention relates to an IC test device, particularly to a probe card structure probe provided with multiple probe head structures.
2. Description of the Prior Art
In semiconductor fabrication, wafer sort is referred to a technology testing the integrated circuit (IC) on a wafer to guarantee that IC can operate normally and learn the yield of products. Normally, an automatic test equipment (ATE) is temporarily electrically connected with IC on a wafer to verify the performance of IC. A probe card is used to transmit signals between ATE and IC.
Refer to FIG. 1A. In a conventional wafer sort, probes 1100A of a probe card 1000 are interposed between and connected with a printed circuit board structure 2000 and a tested wafer 3000, which are separated from each other by a predefined/fixed probe depth HPD. The probe 1100A has a specified diameter-to-length ratio so as to maintain the stiffness of the probe 1100A and favor the connection of the probe 1100A to the printed circuit board structure 2000 and the wafer 3000. With continuous advancement of semiconductor technology, chips are persistently miniaturized to smaller and smaller size. Therefore, it is necessary to reduce the related dimensions of a probe card for wafer sort. Refer to FIG. 1B. The size and spacing of electrodes in the testing area 2100B in the wafer side of the printed circuit board structure 2000 in FIG. 1B are smaller than the size and spacing of electrodes in the testing area 2100A in the wafer side of the printed circuit board structure 2000 in FIG. 1A. Thus, the diameter of the probe 1100A in FIG. 1A must be reduced to the diameter of the probe 1100B in FIG. 1B so as to meet the new situation. In the case that the probe depth HPD and the dimensions of the probe card are unchanged, the diameter-to-length ratio of the probes 1100B must be reduced, which will further reduce the stiffness of the probes 1100B and affect the connection of the probes 1100B to the printed circuit board structure 2000 and the wafer 3000. Thus, the quality and result of wafer sort is also affected. Besides, in the conventional wafer sorting, one probe head is just used for testing one wafer so that the conventional probe head cannot be utilized for 3D IC testing purpose, especially taking die-to-wafer or chip-to-wafer for example.